Thursday 7 June 2012 10.59 EDT
First published on Thursday 7 June 2012 10.59 EDT

The US defence secretary has raised the pressure on Pakistan over insurgent bases along its border with Afghanistan, saying Washington is running out of patience.

"It is difficult to achieve peace in Afghanistan as long as there is safe haven for terrorists in Pakistan," Panetta said on a visit to the Afghan capital, Kabul.

"It is very important for Pakistan to take steps. It is an increasing concern, the issue of safe haven, and we are reaching the limits of our patience," Reuters quoted him as saying.

Panetta is on his fourth trip to Afghanistan since taking up his current role, to get an assessment of progress in the war from the top US and Nato commander, General John Allen, and to discuss plans for the withdrawal of US troops.

About 23,000 American soldiers are due home by the end of September, leaving 68,000 still in the country. Nato combat troops are due home by the end of 2014, but the pace of the next phase of the withdrawal has not yet been decided.

It depends in part on progress in training Afghan troops and holding off the insurgents. The Afghan defence minister, Abdul Rahim Wardak, said Pakistan would play a key role in that, and he appealed for more help from his neighbour.

"If that co-operation starts, we will be able to disrupt their command and control, disrupt their training, disrupt their weapon recruitment and also will be able to eliminate or capture their leadership," he said at a joint news conference with Panetta.

"Without doing that, I think our endeavour to achieve victory will become much more difficult," the Associated Press quoted him saying.

Insurgent groups fall back across the border to escape bitter weather or heavy offensives, to rest and pick up extra supplies of weapons, food or cash. They have strong bases despite regular forays by US drones into Pakistani airspace.

The explicit and repeated criticism of Pakistan, after similar complaints during a visit to India, could signal US willingness to up the tempo of the drone strikes. A recent increase in strikes on insurgents in Pakistan was due in part to frustration with Islamabad, the Associated Press said, citing an unnamed senior US official.

Panetta arrived after a day of violence that emphasised the vulnerability of Afghan civilians in the decade-long war. At least 21 people were killed by Taliban suicide attacks on a bazaar in southern Kandahar city, and another 18 by a pre-dawn Nato air strike on a house where members of a wedding party were staying in the east, Afghan officials said.

Hamid Karzai, the Afghan president, cut short a trip to China to deal with the aftermath of the attacks, and issued a strong condemnation of the bombardment, which he said claimed 18 innocent lives.

"Nato operations that inflict human and material losses to civilians can in no way be justifiable, acceptable and tolerable," Karzai said in a statement. Nato has said only that it is looking into reports of civilian deaths.

The president has long criticised Nato for not doing enough to prevent the killings of civilians. His critics in turn say he should be stronger in his condemnation of the Taliban's role in pushing up the country's civilian casualty toll. Insurgents are now responsible for more than three-quarters of these deaths, according to UN figures.

Karzai said he was "deeply grieved" by the deaths caused by the Taliban bombing in southern Kandahar city, but he did not condemn the insurgents or the attack.